In the construction industry, lateral support surfaces or floors are often elevated above the substrate on which they must ultimately be supported. The substrate is ordinarily ground, soil, fill dirt, or the like. Occasionally, the floor can be supported directly on a leveled substrate or ground by a concrete pad. Under these circumstances there may not be a foundation, nor is there any need for a support pier for the horizontal girder or floor. More commonly, the floors are raised above ground level or the substrate support level. A durable rigid material, such as plywood or flooring, will be supported at intervals by a lateral girder. These can be floor joists, 2×4's, 4×6's, metal girders, wooden girders and the like. Periodically, these lateral girders must receive support not only at the ends but also at points along the length of the lateral girders. For example, in a crawl space under a house, the foundation will ordinarily be concrete blocks or concrete piers. Lateral girders will run from one support pier to another support pier. The floor surface may be mounted on these lateral girders, either directly or there may be intervening floor joists. However, ultimately the entire weight supported by the structure must be supported by the concrete piers, wood posts, or whatever else is vertically sunk into the ground or substrate.
On occasion, the lateral girder may begin to sag. This can arise from a variety of causes. First, through poor design or miscalculation of the loads these lateral girders are required to carry, they may simply not be strong enough to support the weight which is placed on them in the area between the points of vertical support piers or posts and the point the load is applied. Secondly, there may be settling of the vertical support piers or posts. This can happen from a variety of causes. The soil can be soft and, as weight is applied, the vertical post can sink further into the soil. The concrete footers which may support the piers may not have been large enough to begin with. The soil can shrink over time so that the vertical piers, instead of supporting the lateral girder, will settle and allow the supported girder to sag.
When there is sagging of the lateral girder, it may be possible to use a jack, ordinarily hydraulic, to raise the lateral girder beam and to place shims between the vertical piers and lateral girder. However, this is simply a temporary fix since there may be more settling over time. Consequently, there is a need for a permanent way of providing support from the ground to a lateral girder where, for whatever reason, the girder is sagging.